1. Field of the Invention
Embodiments of the invention relate to a substrate position aligner. More specifically, embodiments disclosed relate to methods and apparatus for aligning vertical substrates.
2. Description of the Related Art
Substrate handlers are commonly used in semiconductor manufacturing in order to transfer substrates through the various processes of manufacturing. The substrate handlers typically include transfer robots with substrate grippers for holding the substrate by the substrate's edge. However, substrates often include a cut, such as a flat or notch, made into one or more sides to indicate the crystal orientation, and in some instances the doping orientation, of the substrate. As such, in vertical orientation processes, for example cleaning modules in chemical mechanical polishing (CMP) systems, the orientation cut in the substrate may interfere with the substrate gripper causing the substrate to be improperly held or even dropped. This poses a challenge, particularly in the processing of 150 mm substrates, where the length of the orientation cut is long relative to the substrate diameter, thus making it both difficult to rotate the substrate on center, and to properly grip the substrate while avoiding the orientation cut.
Thus, there is a need for methods and apparatus for improving the ability of substrate grippers to hold vertical substrates.